PROMARV MNTHEMATOGS 3B
Primary Mathematics Proiect Team Project Direcior Dr Kho Tek Hong Team Members Chee Kum Hoong, Heclor Chip Wd Lung Liang Hin Hoon Lim Eng Tann Lim Hui Cheng, Rosalind Ng Hwee Wan Ng Siew Lee
Curriculum Specialists Cheong Ngan Peng, Christina Ho Juan Beng
::ll
Curriculum Planning & Development Division Ministry of Education, Singapore
ffirr"EP,5SA,t An inorint of fines Media
of Singapore Curriculum Development 'nslitule Curriculum Planning & Development Dlvision Ministry ol Education, Singapore
@ 1982, 1993 @ 1997,1999
Pub ished by
Times lvledia Privale Limit€d
Anember of the Times Publishing Grcup Times Cenire 1 New lndust al Road Singapore 536196 E-mail: lps @ tpl.corn.sg On ne Book Slore: hltp://www.timesone.com.sg/fpl First publlshed Second Edilion Th rd Ed Repr
tion nted
1982 1993 1999 2000, 2001 (lwice)
Al
rig his reserved. No parl ot th s publication may be reproduced, slored n a retrieva sysiem, ortransmilted, in any form or by any means, eeclronic, rnechan cal, p"oLocopy 19. re.o'dirq or orl_prw sF. wrtl oullhF prio' perm sson of the p!blishers.
tsBN 981 01 8050 0 Prinled in Singapore by C.O.S. Pinterc Pte Ltd
llluslrator Pau Yong
ACKNOWLEDGEMENTS The project ieam would like lo record their thanks to the loLlowing:
. . .
members of the Primary l\,4alhematics Tearn who developed the iirst edilion and second edition of the package members oi the Steering Committee for the second ediuon of the package
teachers who tested the materials in the package and provided useiul jnsights and suggestions
. .
Educational Techno ogy Division, components ol the package
lor the design and production of the audio-visual
all those who have helped in one way or anoiher in the development and production of the
package
PREFACE The Primory Mothemdtics Pockoge comprises textbooks, workbooks, teocher's guides ond oudio-visuol moteriols.
The moin feoture of the pockoge is the use of the Concrete Pictoriol + Abstrqct opprooch. The pupils ore provided with the necessory leorning experiences beginning with the concrete ond pictoriol stoges, followed by the obstroct stoge to endble them to leorn mothematics meoningfully. Like the previous editions of the pockoge, this edition encouroges octive thinking processes, communicotion of mathemoticol ideos ond problem solvinq. This textbook is cccomponied by two workbooks ond o teocher's guide. lt comprises 9 units. Eoch unit is divided into ports: @, @, . . . Eoch port storts with o meoningful situotion for communicotion ond is followed by specific leorning tosks numbered 1,2, . . . fhe srg n
is used to link the textbook to the workbook
exerctSes.
Proctice exercises ore designed to provide the pupils with further proctice ofter they hove done the relevont workbook exercises. Review exercises ond revision exercises ore provided for cumulotive reviews of concepts ond skills. All the proctice exercises. review exercises cnd revision exercises orp nnlionnl eyer.i
The colour patch I is used to invite active porticipotion from the pupils ond to focilitote orol discussion. The pupils ore odvised not to write on the colour potches.
CONTENTS Mentol Colculotion
1 2 3 4
Additlon Subtroction Multiplication Division
6 8 10
PRACTICE 1A PRACTICE 1B
12
11
Airport
Length 'l ' Metres ond Centimetres PRACTICE
2
13
14
24
18
Kilometres
19
PRACTICE 28
23
Weight
'l
Kilogroms ond Croms PRACTICE
2
24 28 29 33
34
More Word Problems PRACTICE 38
Review A
34
Review B
35
Cqpocity Litres ond Millilitres PRACTICE
44
PRACTICE 48
Review C
@@ffiffi
36 42 43
44
6 8 t0 l1
Grophs Bor Crophs
45
Froctions 1 Froction of o Whole
fl
PRACTICE
2
t2
t3
64
56 57 62
Equivolent Froctions PRACTICE 6B
Review D
63
Time t4 t8 t9
1
Hours ond Minutes PRACTICE
2
74
Other Units of Time PRACTICE 78
r3
Review
E
fiffi n
65 73 74 76
77
Geometry t8 t9 i3 14
t5
|6 12 L?
t4
1 2
Angles Right Angles
79 81
Areo ond Perimeter
1 2 3
Areo Perimeter Areo of o Rectongle PRACTICE 9A
Review
F
83 88 92
94 95
Mentol Cqlculqtion
O
Addition Add 46 ond27.
o
a@w
@
ffi@
awffi
a@@
46
27
a@@
.WW 46+27
207 Add 20 to 46 first.
""m +O
+2O OO ++7
-------------+
/5
46+27=a
6
1. (o) 23 *'0, I *4, I 23+14=a
s419- I *6, 1
16)
5++36=l (c) 38 -119,
I *s, I
38+45=l 2. (o) Whot number is 3 more thon 68? (b) Whot
3.
number is 20 more thon 94?
Add.
(o) 43 + 30
(b)
(s)36+23
(h)27+3s
(d)72+s
20 (e)33+7 67 +
(c)
85 + s0
(f)64+8 (D ss+26
f ilil;ili 4.
Find the sum of 58 ond 16.
58+16=l
s.
Add.
(o)
39 +
27
(b)
sB +
34
(c)
4s + 6s l-
-",b""k
',.*-
\
@
Subtrqction Subtroct 34 from 87 .
OW ow oaw oa ww aa @w t--Y
a7
,/\
304
]
a7
Subtrqct 30 from 87 first.
-30 6t-5l-..._5J S7
1.
-4
-34=l
(o) 6s ---l!-
I -', I
O5-12=l rhr
-34
za -i0 . I
-5. I
t6-46=l I -t, I 03-28=l
(c) 6: --?9;
8
2. (o) Whot number (b) Whot
3.
A
tess fnon 5 t( 30 less thon 76?
Subtroct.
(o) 70 - 30 (c) 68 - 60 (e) 83-3
(b) ss -70 (d) s8 -6
(f)
47 _J
(b) (d)
64 s6 63
Subtroct.
lo) 46 (c\ R7 5.
number
z
52
(f)
47
-34 -55
Find the difference between 90 ond 18.
90-18=l
o.
Subtroct. /'n\ ?O 2a (c) 70 65 (e) a0 29
(b) 60 (d) s0 -
- It] a0@) (D s0- 39
(f)
(h)
9
80 70
-
s6 17
s8 s8
Multiplicqtion
3 tens x 4=12tens
30x4=I r. to) rvrurupry b rens oy 5.
6tensx5=ltens
60r5=l
(b) Multiply 4 hundreds by 3.
4 hundreds
;
3=
|
hundreds
400x3=l 2.
Multiply.
(o) 8x7 (d) s0x9
(s)
600 x 3
(b) (") (h)
80x7 40x8 300x5
(c)
800 x 7
(f) 90x6 (D 7oox4
f;;.,,*.^* 10
'-
@ Division \
$ bt
6tens:3=2tens
60*3=l '1.
(o)
Divide 8 tens by 4.
8tens=4=ltens
80*4=I fo
(b)
Divide 6 hundreds by 2.
I
6 hundreds = 2 =
!
hundreds
600*2=l 2.
Divide
(o) 9+ 3 (d) 40+2 (9) 320 + 8
(b)
90-3 360-6
(h) 24OO + 4
(c)
(f)
(i)
900 + 3 400 - 10 1oo0
-
lilil;;; 11
5
-\
PRACTICE 1A Find the volue of eoch of the following:
(o) 1. 65+28 2. 99+99 3. 78-45 4. 99-98 5. 4x30 6. 500 - 5 7. 100x6 8. 160+8 9. 6x100
(b) 34+66 99+98 90-56 83-75 50x8 600: 10 5x90 240-3 40x6
(c)
18+84
27+45
90-85 98-97
200x9 400
_
2
300x7 810+9 500x5
10. (o) Whot number is 29 less thon 84?
(b) Whot number is 68 less thon 310? (c) Whot number is 35 more thon 475l, (d) Whot number is 97 more thon 5397?
11. There cre 80 poges in one exercise
book. How mony poges ore there in 6 exercise books?
12. A shopkeeper pocked 200 onions equolly into 5 bogs. How mony onions were there in eoch bog?
13. Mr Wu sold 70 buns on Fridoy. He sold 4 times os mony buns on Sundoy cs on Fridoy. How mony buns did he sell on Sundcy? 12
PRACTICE 18 Find the volue of eoch of the followinq:
(o)
t.
fu
2. 40 3.6
(b) 3 2
X
90 q
60 80 7
(.)
x5
+4 x
400
+8
30 x6 600 +-3 300 x8 720 +-9
4.
270
5.
Alice soves $50 o month. How much does she sove in 8 months?
6.
A coke shop sold 200 koyo buns. It sold 4 times os mony koyo buns os chocolote buns. How mony chocolote buns did it sell?
320
7. A fruit seller bought 9 boxes of peors. There were 40 peors in eoch box. How mony peors did he buy cltogether?
8.
There ore 6 coins in o set. How mony coins ore there in 200 sets?
9.
Mr Fu pocked 250 tomotoes into pockets of 5 eoch.
(c) (b)
How mony pockets of tomotoes were there? He sold oll the tomotoes ot $2 o pccket. How much money did he receive?
10. (o) Mr Lin bought 98 blue pens ond 62 red pens. How
(b)
mony pens did he buy oltogether? He divided the pens equolly into 8 boxes. How mony Dens were there in ecch box? 13
Length
O
Metres ond Centimetres Cet o metre ruler ond find out how lonq 1 metre
is.
Estimote the length of the cholkboord in the clossroom. Then check by meosuring it with the metre ruler.
l=lHl=l riF:?l
ls the length closer
to2mor3rn?
Estimote the height of the door in your clossroom. Check by meosuring. ls the door 2 m high?
14
The metre (m) ond centimetre (cm) ore units of length.
1m=100cm
1.
2.
1m 25 cm. 1m2s cm I cm more thon 1 m.
Ali's height
IS
(c) (b) 1m2s
cm
1..
(o) Write 2 m in centimetres.
(b)
261 =lcm Write 300 cm in metres.
3OOcm=lm 3.
Wolk 5 steps. Mecsure the distonce in metres ond centimetres. Then write the distance in centimetres. ,,15
4. Hoshim's long jump result is 1 m 45 cm. Write the distonce in centimetres.
1m45cm-1..
5.
Write in centimetres.
(o) 1m90cm (b) 1 m55cm
(d) 2m89cm (e)
3
m8cm
(c) 2m
(fl
86 cm
am 6cm
6. A cor is 395 cm long.
Write the length in metres qnd centimetres. /-
I
395cm-lmlcm
\-
7. Write in metres ond centimetres.
cm (d) 299 cm (o)
180
(b) (e)
195 cm 304 cm
^_---*:-----\ JUUcm=Jm
oJ
(c)
(f)
I
262 cm 409 cm
8. The tqble shows the results of the shot put finols.
Arronge the distonces in order. Begin with the shortest.
t;il"k,*;; \
9.
Lily hos o piece of red ribbon 3 m 40 cm long ond o piece of yellow ribbon 1 m 85 cm long. (o) Find the totol length of the ribbons. 3m40cm
1m85cm
3m40cm+1m85cm=lmlcm
The totol length of the ribbons is
(b)
How much longer 3m40cm
is
I
m
!
the red ribbon thon the yellow ribbon?
1m85cm
3m40cm_img5cm=lmlcm
l..^- .l ''.,
".
The red ribbon is I the yellow ribbon.
cm.
o;
"r:++
rn
I
1l
,
;
cm longer thon
PRACTICE 2A
1. Write in centimetres.
(o) (d)
2.
(b) 1m40cm 4m 3m95cm (e) 4m5cm
(c)
(f)
Write in metres ond centimetres. (o) 120 cm (b) 225 cm (d) 618 cm (e) 963 cm
m25cm e m9cm 2
(c) 309 cm (f) 405 cm
3. Find the missing numbers.
(o) (b) (c)
(d) (e)
(f) A
1m-65cm-lcm 1m-55cm-lcm 2m- 1m75cm-1.. 2m-95cm=lmlcm 3m- 2m92cm-1.. 3m40cm-6cm=lmlcm
Add or subtroct in compound units. (b) 3 (o) 2m75cm +3m (c) 1m26cm +2m65cm (d) 4 s (e) 5m85cm (g) 2m55cm -1m50cm(h) 3
m4cm+65cm m8cm+1m95cm
(f) m90cm-76cm
-5m
m6cm-2m25cm
5.
Rohim is 1 m 60 cm toll. Roju is 16 cm shorter thon Rohim. Whot is Roju' s height?
6.
Mr Chen tied two porcels with these strings. 1m80cm
1m65cm
Whot wos the totcl length of the strings? 18
O
Kilometres The kilometre (km), metre (m) ond centimetre (cm) ore units of length.
&=
1km
tm
A bus is obout'10 m long, The totol length of 100 buses is obout 1 km.
r-
We meosure long distonces in kilometres.
19
1.
740
1010 m
m ---- !
Jordine Steps
(o)
The distonce between Sentoso ond Jordine Steps
(b)
The distonce between Mount Fober ond Sentoso
islkmlm. islkmlm.
23 km
42 km
(c)
The distonce ocross Singopore is obout
fo eoSt. It is cbout
(b)
f
I
km from west
km from north to south.
The distonce from the Bird Pork to Chongi Airport is obout km.
I
20
3.
Sentoso
+.i =.:. ti;t:;
I
i
runr
i
Der
i l
.i ii itj'
The totol length of the Monoroil route on Sentoso lslond is obout 6 km 100 m. Write the length in metres.
k---aa*;)
4.
The distonce oround o running trqck is 400 m. Roju ron round the trock 3 times.
Heronlkmlm. (m
5.
Write in metres. (o) 1 km 600 m
(d) 3kmSsm
6.
(b) 2km 550 m
3km 20m
(c)
2 km 605 m
(f) 4kmsm
Write in kilometres ond metres.
(o) 1830 m (d) 30s6 m
(b) 23O4 m (e) 3040 m
21
(c) 2780 m
(f) 4009
m
2km450m Army Ccrmp
1km850m Post Office
Librory
Find the distonce between the ormy comp ond the librory.
2 km 450 m + 1 km 850 m =
|
km
I
m
The distonce between the ormy comp ond the librory is
!kmlm.
'1
km40m
School A
920 m MRT Stqtion
Which school is neorer to the MRT stotion? How much neo rer?
1km40m-92Om=lm School B is
!
m neorer to the MRT stction. 22
School
B
PRACTICE 28
1.
Write in metres.
(o) 3 km (d) 2km60m
2. Write in kilometres (c) 1680 m (d) 30e0 m
3.
(b) (")
1km450m
3km78m
(c)
(fl
2 km 506 m
akm 9m
ond metres.
(b) 1085 m (e) 3999 m
(.)
2204 m (f) 4001 m
Find the missing numbers.
1km-800m=lm 1km-600m=lm (c) 2km-1km45m=lm (d) 1km-40m=lm (o) (b)
(e) 5km-4km94Om=lm
(f) 2km-275m-lkmlm 4. .
Add or subtroct in compound units.
(o) (b) (c) (d) (e)
:e
w
(f)
2km650m+3km 3km460m+50m 3km300m+800m km700m+1km300m
5km950m-4km
kmS2Om-72Om
(g) 6km25m-3km35Om (h) 5km40m-3km990m
5.
Find the distonce between the gun boot ond the Iighthouse.
2 km
940
4km400m :E&23
?4
Weight ,-,
It
Kilogroms ond Grqms The kilogrom (kg) ond grom (9) ore units of weight.
lkg=lQggg
The porcel weighs 650 g.
The gropes weigh
ls.
The popoyo weighs
lksIs.
'1. Reod the scoles. (o)
(c)
2. The pototoes weigh
2 kg 200
Write the weight in groms.
3.
9.
2kg=2OOOg
Eoch book weighs 350 g. The totol weight of 4 books
islkgle.
f;;r;G,r \ 25
4.
A bog of peonuts weighs
1 k9 850 g. How much more peonuts ore needed
to moke up 2
a-':
'
kg?
lkg- 8sos=19
2ks-lkgsso9=ln
1kg25O
1100 9
g
Which is heovier, the fish or the chicken? How much heovier?
2ks600s
lkgsOOg
(o) Whot is the totol weight of the onions ond the tomotoes? (b) Whct is the difference in weight between the onions ond the tomatoes? 26
7.
3k980q
(o)
1k99609
Find the totol weight of the wotermelon ond the DqnonoS.
3ks80s+1k9960s=l
The totol weight is
(b)
I
Find the difference in
kg
I
ksls
g.
weight between the wotermelon
ond the bononos.
3kg
809-1ks9609=IksIs
The difference in weight is 2/
!
kg
|
9.
f*"*;",*;; \
PRACTICE
34
1. Write in groms.
(c) 1 ks 4s6 9 (d) 2ke80s
2.
3.
(b) 2 ks 37o s (e) 1kg8s
Write in kilogroms ond groms. (b) 13sa e @) 21a3 s (d) 2206 e (e) 308s s
3k9808q (f) 4k97 9 (c)
(c)
(f)
3800 s 400e I
Find the missing numbers.
(o) 1k9-395s=ln (b) lks-85e=ln (c) 3ks -2ks4oos=fs (d) sk9 -4ks60s=lg (e) 1k9-540 s=f s (f)
4.
3k9-805s=lksIs
Add or subtroct in compound units. (o) 3 kg 500 g+2kg (b) +ks650s+4509 (c) 3k9 1009+1k99009 (d) 2ks 509+4ks70s (e) 3k9 109-2O09 +ks300s-1ks50g (s) 4 k9 25o s 1 k9 s00 9 (h) 5 ks 2 k9 905 9
(f)
-
-
5.
Lily weighed 25 kg 750 9 two yeors ogo. Now she weighs 32 kg. How much weight hos she goined?
6.
A jockfruit weighs 2 k9 990 g. A wctermelon weighs 4 kg 200 g. (o) Find the totol weight of the jockfruit cnd the wotermeton. (b) Find the difference in weight between the jockfruit ond the wotermelon. 28
More Word Problems
2kg
t)P lkg
350 g
w.=., .,:
::.::.1
1kg 20O g
Weight of morbles = 1 kg 20O 9
=19 29
-
350
9
1. A bottle of souce weighs 560 g. The empty bottle weighs 305 g. How mony groms of souce ore there in the bottle?
2. A bosket of fruits weighs 1 k9 60 g. The empty bosket weighs 200 g. Find the weight of the fruits. 3. Mr Wu's weight is 57 kg. He is 3 times os heovy os Sumin. Whot is Sumin's weight?
suminW \-1.-, ?
3 units = 57
kg
lunit =lk9
Sumin's weight is A
I
kg.
A wotermelon is 5 times os heovy os o popoys. lf the popoyo weighs 950 g, find the weight of the wotermeton. Wotermelon
eopoyoW :.--:
.95O9 1 unit
= 950 g Weight of wotermelon = 5 units
lg
=lksIs 30
34 k9 600 g. He is 800 g heovier thon Dovid. Whot is Dovid's weight?
5. John weighs
.Joh
n
Dovid
? Dovid's weight
-
34 kg 600 g - 800
800 g
g
=lksIg
o. A goose weighs 3 kg 200 g. A duck weighs 1 kg 800 9. (o) Whot is the totol weight of the goose ond the duck? (b) Whot is the difference in weight between the goose ond the duck? 3 kg2oo g Coose
Duck
1k98009
7.
A durion weighs 2 kg 50 g. A jockfruit is 600 9 heovier thon the durion. (o) Whot is the weight of the jockfruit? (b) Whot is the totol weight of the two fruits? Du rion
.Jockfruit
600 q
8. The totol weight of o pocket of flour ond q pocket of solt is 2 k9 4OO 9. lf the pocket of flour weighs 1 kg 950 g, find the weight of +L^ -1.^+ (Jr ^f -^l+ Lr rE ^^ >urL. PuLr\EL 2k940Og
1kq9509
totol weight of o footboll ond 10 tennis bolls is 1 kg. lf the weight of eoch tennis boll is 60 9, find the weight of
9. The
the footboll.
6og
Weight of 10 tennis bolls = 60 x 10 = 600
I
Weight of the
footboll -
1 kg
=lg
10.
-6009
The totol weight of o tin of cooking oil ond 2 pockets of sugor is 5 kg 50 g. If the weight of eoch pocket of sugor is 2 kg, find the weight ot the tin ot cooking oil.
wergnr oT z pocKers oT sugor = Weight ot the tin of cooking oil =
T T kglg Kg
f;il;;;; 32
\
PRACTICE 38
1. Write in
(o) (d) 2.
3.
9roms. s ks 2 ke 80s e
(b) 1k99509
2k959
Write in kilogroms ond groms. (o) 1s0s (b) 10ss s (e) 3sss s (d) 33e0
s s
(.)
1kg60g
(f)
3k929
(c)
2208 I
(f) 5002
I
Add or subtroct in compound units.
(o)
G)
2ks9409+300s
aks-1ks480s
(b) 3k98809+1kg22os (d) skg20s-2ks45o9
AB (o) Find the totol weight of the two porcels. (b) Find the difference in weight between the two porcels.
5.
The totol weight of Ali ond Somy is 100 kg. lf Ali's weight is 46 kg 540 g, find Somy's weight.
6.
Roju's weight is 70 kg. He is 5 times os heovy os his son. Find the totol weight of Roju ond his son.
t.
Dovid weighs 39 kg. Hosson is twice os heovy os Dovid. Mingli weighs 27 kg less thcn Hosson. Whot is Mingli's weight? 33
REVIEW A Find the volue of eoch of the following:
(o)
1. 499 + 2. 750
3. 4.
53 87
(b)
42 145 7 5
(c)
507 + 3593 1806 82 156
5
104
8
3084 +63 7009 -5 407
324
x4
+6
5.
There ore 24 boxes of chocolotes in o corton. How mony boxes of chocolotes ore there in 8 cortons?
6.
5 people shored $450 equclly. How much money did eoch person receive?
l.
Mrs Lin gove eoch of her friends 7 cup cokes. She gove owoy 140 cup cokes oltogether. How mony friends did she give the cup cokes to? 8 boxes of yellow ond green buttons. There ore 46 buttons in eoch box. lf there ore 200 yellow buttons, how mony green buttons
8. There ore
ore there? 9. There were
l50 bulbs in o
box.
6 of them were broken. The rest were pocked into boxes of 4 bulbs eoch. How mony boxes of bulbs were there? 10.
Mr Wong bought three There were 36 oronges There were 54 oronges How mony oronges did
boxes of oronges. in the first box. in eoch of the other he buy?
two
boxes.
REVIEW B Find the missing numbers.
1.
2.
(o)
5m-lcm
(b)
(c)
2km560m=lm
(d)
(e)
1k930g=lg
(f)
(o)
-lm lcm 32Ocm -!m lcm 1850m=lkmlm 2OO4m-lkmlm
(b) (d)
4m8cm-I.. 3km5rn=lm 2 kg B0 g=lg
208cm
3095 (f) 4209
9 9
=lks ls =lks ls
Add or subtroct in compound units.
3. (o) 1m58cm+7Ocm (c) 3m-2m35cm a.
(o) 5 (c) 9
km690m+520m (b) 7 km 960m+2km24Om km42Om-780m (d) 8 km 30m-3km4B0m
s.(c) 4kg92Og+1259 (c) 6kg-4kg82Og
6
(b) 2m 95cm+2m45cm (d) 4m 5Cm-lm65Cm
(b) (d)
3k97609+4kg35Og
4k9259-2k923O9
(o) The totol weight of the fruiLs is | 9. (b) If the opple weighs 90 9, find the totol weight of the two peors. (c) lf the peors ore of the some weight, find the weight of eoch peor.
35
Copccity Litres qnd Millilitres How much woter is there in eoch of these beokers?
Whot is the totol omount of wcter in ecch set of beokers? (o)
WffiffiW
36
WW. W,W
WW1fl
1f=10O0ml 1.
Cet some poper cups. Find out how mony poper cups you con fill with 1 litre of woter.
WW 2.
Cet o poil. Find out how much woter the poil con hold.
3.
The bottle holds 2 litres of worer. Its copocity is I litres. 37
F,n".-;;; \
The cqpocity of o contqiner is the omount it con hold.
4.
We meqsure copocity in litres qnd millilitres.
(o)
-
The copocity of the mug is
I
ml.
(b)
The copocity of the bottle is
I
ml.
(c)
'OeSg(
D
The copocity of the jug is 38
I fI
ml.
E
(o) (b)
Cet o bottle which holds less thon 1 litre of woter. Estimqte ond then meosure its copocity. Cet o bottle which holds more thon 1 litre of woter. Estimote ond then meosure its copocity.
[*"*ffi**;"i;-
6.
Find the
totol omount of woter in these two beokers.
5mm
700m| +400m|
-lml
=lzlml 7.
Write '1500 ml in litres ond millilitres.
1500mt
=lrlml
8. Write in litres ond millilitres.
(o) (d)
1200 100s
ml ml
(b) 2s00 (e) 3a00
9. (o) Write 2 f in millilitres. 2 ( -lml (b)
ml ml
( 35O ml in millilitres. 2(3sOml -lml
Write 2
39
(c) 2050 ml (f) 3105 ml
10.
Write in millilitres. (o) 1 { 800 ml
(d)
3
425ml
(b) 148Oml
245ml
(c)
(f)
1a 8ml 3( 500 ml
11.
Eoch pocket contoins 250 ml of milk.
The totol omount of milk in 5 pockets is
I fI
ml.
12.
WWWW How mcny millilitres more woter ore needed to moke up 2litres? 13.
Which contoiner con hold more woter? How much more?
@b".r*d;;at\ 40
14.
(o)
Find the
1l800ml
3{350m|
A
tt
totol copocity of the two contoiners.
=lrl The totol ccpocity is I f I ml. 1{8OOml +3{350rnt
(b)
Find the difference in copocity between the two
contoiners.
o
=lrlml
3{350ml -1(
8OOmt
The difference in
copccityislflml. [;;il;.*"*,,.-\ 41
PRACTICE 4A
1. Write in millilitres.
(a) 3 t (d) 2 e 6so mt
1
3.
(b)
1( 200 ml
(e)
34 65 ml
Write in litres ond millilitres. (o) 5000 ml (b) 1600 ml (d) 320s ml (e) 2074 ml
@) 2e 55 mi (f) 4r 5ml
(c)
(f)
2250 ml
'1009 ml
Circle the correct cnswer.
(o) 1 { is more thon,/equol to,/less thon 980 ml. (b) 2 f 50 ml is more thon/equol to,/less thon 2O5O ml. (c) 4 I 8 ml is more thon/equal to./less thqn 4800 ml. 4. Add or subtroct.
(a) 1 t
s00 ml + s00 ml 3 c 300 ml + 750 ml
(b) 248OOml (d) 5/900ml
+1{200m| +3(24Oml
(c) (e) 24 800m| -1{780m| (f) 4(-1(85Oml G) at BOml -11360m| (h) 6{5mi -2(80ml
5.
The toble shows the copocities of four contoiners.
(o, Which contoiner hos the greotest copocity? /h) Which contoiner hos the smollest copocity? (c\ Whot is the totol copocity of the four contoiners? 42
PRACTICE 48
1.
The cooccitv of Contoiner A is 2 4 650 ml. The cooocitv of Contoiner B is 5 { 300 ml. (o) Whot is the totol copocity of the two contoiners? (b) How much more woter con Contoiner B hold thon Contoiner A?
2.
Contoiner X holds 2 (, 8OO ml of woter. Contoiner Y holds 1 { 600 ml more woter thon Contoiner X. How much woter does Contoiner Y hold?
3.
Mrs Chen fills o contoiner with 9 bottles of oronge juice. Eoch bottle conloins 2 litres of orcnge juice. Whot is the copocity of the contoiner?
4.
The copocity of o poil is 6 litres. 5 poils of woter ore needed Lo fill up o tcnk. Whot is the copocity of the tonk?
5.
The copocity of o contoiner is 24 litres. How mony poils of woter ore needed to fill up the contoiner if the copocity of the poil is 3 Iitres?
6.
The copocity of o contoiner is 8 litres. It contoins 4 4 650 ml of wcter. How much more woter is needed to fill up the contqiner?
7.
Mr Li bought 6 tins of pcint. Eoch tin contoined 3 litres of point. He hod 2 4 4OO ml of pcint left after pointing his house. How much point did he
use?
REVIEW C Find the volue of eoch of the following:
(o)
1. 895 2. 1436 3. 77 4. 900 5.
(b)
so37 437 4 2
6409 + 399
3002
2846 + 754 5362 -26 123 x5
518-8
Mr Chen received $504 for selling pens ot $8 eoch. How mony pens did he
6.
-78
t3 x9 408 +3
(c)
sell?
Mr Wu poid $628 for o television set ond 91485 for o computer. He hod $5'15 left. How much money did he hove ot first?
7.
Mrs Chen bought 4 boxes of cookies. There were 12 chocolote cookies ond 8 peonut cookies in eoch box. How mony cookies were there oltogether?
8.
Mr Li sold 337 pockets of biscuits lost month. He sold 299 more pockets this month thon lost monfn. How mony pockets of biscuits did he sell in the two months?
9.
Solly bought 200 eggs to moke cokes. She used 8 eggs to mcke eoch coke. (o) How mony cokes did she moke? (b) lf she sold oll the cokes ot $10 ecch, how much money would she receive?
Grophs
O
Bor Grophs ;@"2 (4
Kt*-fl4j a
This picture groph shows the number of fish cought by
four boys. .. .
ffi "i.
ton
Somy
How mony fish did eoch boy cotch?
Yonghuo
This bor groph shows the some informotion.
12
10
8 Number
offish
6
4 2
0
Minghuo
I
Minghuo cought
fish.
Yonghuo cought
I
They cought
I
Somy
fish.
I Somy cought I Rohcn cought
KOnO n
fish.
fish.
fish oltogettrer.
I more fish thon Somy. Minghuc cought I fewer fish thcn Rohon. I cought the most fish. I cought the fewest fish. Minghuo cought
46
Yong
h
uo
1. This bor groph shows su
Rohim's exominotion results for four
biects. 100
90 80 70
60
Morks
50 40
30 20 10
English
Use the groph
MothemoticsScience
Moloy
to complete the following.
(o) Rohim scored I morks in English. (b) He scored I morks in Mothemotics. (c) He scored ! more morks in Mcthemotics thcn in Englilh.
(d) He hod the some score in
I
He scored 10 more morks in
l. His lowest score wos in !.
(f) His highest score wos in (s)
47
ond
I
l.
thcn in Mothemotics.
2.
This bor groph shows Sulicn's sovings for four months.
Moy
June
Julv
Aug ust
010203040506070 Amount in dollors
Use the groph
to onswer the following questions.
(o)
How much did Sulion scve in Moy?
(b)
How much more did she sove in June thon in Moy?
(c)
In which month did she sove $15?
(d)
In which month did she sove the most?
(e)
In which month did she sove twice os much os in August?
(f)
Whot wos her totol scvings for the four months?
4A
3.
This bor groph shows the number of books reod by five children in o yeor.
80 70
Number 60 of books 50
40 30 20 10
0
Use the groph
Dovid
Mory
Meiling
Hosson
to qnswer the following questions.
(o)
How mony books did Siti reod?
(b)
How mony books did Dovid reod?
(c)
How mony more books did Dovid reod thon Meiling?
(d) Who
reod 5 fewer books thon Meiling?
(e) Who
reod the most books?
(f)
Who reod the fewest books? 49
4. This bor
roph shows the number of people who visited o book foir from Mondoy to Fridoy. g
500 450 400 350 300 Number of visitors 250
200 150 100
50 0
Use the groph
(o) (b)
Mon
Tue
Wed
Thu
Fri
to onswer the following questions.
How mony people visited the book foir on Tuesdoy? How mony more people visited the book foir on Friday thon on Thursdoy?
(c) (d)
On which doy wos the number of visitors the smollest?
(e)
On which doy were there twice os mony visitors os on
On which doy were there os mony visitors os on Mondoy? Wednesdoy?
(f)
lf there were 200 odults on Tuesdoy, how mony children were there?
50
Frqctions
O
Froction of o Whole
2 fifths
o whole
How monv fifths ore there in o whole?
3 eighths
o whole
How mony eighths ore there in o whole? 51
1.
(c)
J of the bor is shoded. 3 'r
I
out of the
I
equol porrs.
? = a fifths
(b)
; .f the bor is not shoded.
I is I 3 =|
out ofthe
I
equol ports.
tifths
(c) lwhole=Ififrhs
t=l
5
2.
,.3 (oj
8
I
or tne Dor ts shoded.
of the bor is not shoded.
(b) lwhole-leighths
t=I
8
(c)
Jondlmokelwhole. 52
3.
Whot froction of eoch shope is shoded? (b)
(o)
(h)
tr,';;""".,*.*\ 53
4.
3<- numerotor 4<- denominqtor
In tne Troct|on
3 5^.ts tne t,
numerotor ond 4 is the
denominotor. Nome the numerotor ond denominotor of eoch of these froctio ns. ) 4 q o (b) (oJ ) (c) (d) 10 7
;
5.
Which is greoter,
6.
Which is greoteri
7.
Which is greoter;
t
-or 53
!
or -<
?(
88or -t
54
It is eosy to compore froctions when they hove o common numerotor or o common denominotor.
The froctions
I
I
10.
ono
3 10
nove o common numerotor.
is the smollest froction. is the greotest froction.
The froctions
I I
33
i'7 JO
35 ^l^
ond
1 hove o common denominotor. 9
is the smollest froction. is the greotest froction.
Arronge the froctions in order. fregrn wttn tne smo est.
.,, 2 2
111 \-./
F,
'''
574 8' 8'
tnl \'t
)t3 8
2
-l
CO./l (A\111 \"/
r1'
workbook ExeKces 29 & 30
PRACTICE 6A
'1.
Find the missing numbers.
(o) (b)
2.
ond
I
moke'l whole.
@) $ond
I
moke
*
l
l
l
whole.
Ncme the numerotor of eoch froction.
" fh) .', 10
t'c'\ \'./
9
n
Nome the denominotor of eoch froction.
(o)
q
4
i
(b) ;
at
4. Which froction
I5 g
.,2 or 4 (oJ ;f -5 ).
whole
IondImokelwhole.
1C (n) .", -3
3.
'1
wntcn rroc on -72
(o) .-10
or
l0
7 10
reoter?
@: rs
(.)
or
1
(c)
6
33or85
smoller?
(b)
:
or
1
(c)
10
22
6. Which is the greotest froction?
15 \o) j' j'j ,.4
(b)
111
7. Which is the smollest froction?
(o) l. '' 6
14
(b)
.,; t)t)
56
333 9' 5'
1O
O
Equivolent Froctions Fold o piece of poper into 2 equol ports. Shode 1 port.
{;i\
2 eouql
I
Dqts l
of tn" poper is shqded.
Fold the poper cgoin. 2 out of 4 equql pqrts
o
2 oT..,rne poper rs snooeo. ; Fold the poper ogcin. 4 out of 8 equol
4-
;ul
the poper is shqded.
15
rne rrocuons
12
t,
4
,1
ono
8
hqve different numerotors ono
denominqtors. But they cre equol. 57
?
1
t
4 8
12
t'4
ono
!8 ore equivolent froctions.
Nome some more equivolent
.1
rrocuons or
W ]
of the bor is shoded.
ro)l=! .",
w
z-l
W
3
(b)
(.)
39
zl 5
t2
W
(d) Nome some more equivolent froctions of ?.
3'
58
2. Whot ore the missinq numerotors ond denominotors?
(o)
3
To find on equivolent froction, multiply the numerotor ond denominotor by the some number.
x2
x3
'I',--\
1
3 ..-___, 6
3
x2
3.
',--\
3
x3
Find
the missing numerotor o rd enomtnotor.
(o)
1_l
(d)
4
12
1
3
,'-
2
\u./ ;3 -
(e)
I
9 6
l) 59
(c)
(f)
5
10
3
6
4.
Whot ore the missinq numerotors ond denominotors?
12
To find qn equivolent froction, divide the numerotor ond denominqtor by the some number.
+2 8 ,-1 12
5.
Find the
(o) (d)
6.
8 10
6
.-t
+2
+4
8.'--\ 6
12
2
',---t
+4
numerotor or denominotor.
(b) 1= 8
(.)
{e)
(f)
"12
9
3 5
10 12
^r" Complete the following equivolent froctions wr
-tz
261
T
12
6 The simolest eouivolent frqction of 't2 60
ts
I I
7.
Express eoch of the following froctions in its simplest form.
',2 \o)
+
(e) 1 "12
(b)
I
(c) a
(d) :
(f)
!6
(o) "'
rh) .,
8.
Which is grecter,
9.
Which is grecter,
8
?
10
19 12
:
1o
?q or
4A
2
aot
7, '10
1O. Which froction is greoter? tq?
(oj 5045 -, 11.
(Dl
t
^.
34
(c)
;'-
(c)
;,; 5l
Which froction is smoller?
.,4 7 (o) s' 10 12.
1
.,, (oi j' 11
r
I 6
23
Arronge the froctions in oroer, beginning with the smollest.
\",, g, 2'
{Dl
''
4 61
??')
10' 5
5
PRACTICE 58
1.
Find the missing numerotor In eo ch of the following:
(o) (d)
2.
4
(b)
8
I
4
(")
10
I I
t)
5
6
9
r_I
(c)
3 1
(f)
(d)
9
I I 4
2_ 5
2
4
I
6
(b) ;=
,l
(e)
12
9
T
6
6
(.)
3
3 1
(f)
I I 3
5
Ring the greoter froction.
ro)
?
i,
@:,
q
7
9
(b) ;,
10
?
5
n 2
(f) :,?)
;
6
10 ;, tz
(cJ
4. Arronge the lroctions in order, beginning
I I6
tol "77 tal
(b)
7
2'l 5Z
(d)
111
s' t' 215
;o
Suchen ote
1or..,tne Dre-
2
Who cte c bigger portion of the 62
10
a'4'n
2.or o pre.
Meiling ote
pie?
! ! 5
8
with the smollest
frcction.
5.
6
Find the missing denominotor tn eoch of the TO OWTnq: (o)
3.
1
REVIEW D 1.
Write the numbers. (c) Nine thousond, two hundred cnd ten (b) Four thousond ond sixty
the numbers in words. (b) 3s40 @) 62oa
2. Write
(c)
s028
3. Whot number is 100 less thon 4000? 4. Write the numbers in order, beginning with the smollest.
(o) 4104, 4014, 4041, 4410 (b) 2211, 1112, 2111, 2121 5.
Find the product of 125 ond B.
6.
Find the quotient ond remoinder when 500 is divided by 8.
7.
Whot number must be subtrocted from 55 to give the onswer 44?
8.
(o) (b)
9.
Find the missing numerotor or denominotor.
How mony $10 notes con you get for $200? How mony 5C coins con you get for $1.50?
rl
'"' 4 10.
,', 2
6
I
i2
(c)
Ring the smoller froction.
11 (oJ a'
,,,
4
2q rd) j. .
I
2
\D) j'
',2
tat
7
3
;at
f
63
10 -
tTl
11
11. Find the missing numbers.
4m20cm-lcm (c) 2km9sm=lm (e) 1ks409 =19 (g) 3t 60ml -lml (o)
(b) 2O5cm (d) 1600
m
(f) 2450 s (h)
-lmlcm
=lkmlm
=lksls
2525m|=lrlmt
tz. John bought 6 peors. He gove the coshier $5. How much chonge did he receive? t5-
A bodminton rqcket costs $9.60. A tennis rocket costs 538.40. How much more is the cost of the tennis rocket thon the cost of the bodminton rocket?
14.
The tub contoins 1 litre of ice creom. Peter ond his friends eot 325 ml of it. How much ice creom is left?
15.
Solly bought 10 pockets of milk. Eoch oocket contoined 125 ml of milk. Find the totol omount of milk in litres ond millilitres.
16. Muthu spent.49 of his pocket
money ond soved the rest.
Whot froction of his pocket money did he sove?
17.
Minghuc spent
?
]/
of his money on o book ond the
Test on o
rqcKet.
Whot frcction of his money wos spent on the rocket?
Time Hours ond Minutes
20 minutes post 8
25 minutes to 9
Dcvid storted running ot 8.20 o.m. He rcn 3 km. He finished ct 8.35 c.m. He took'15 minutes to run 3 km. 65
We reod 8.20 os eight twenty. 8.2o is 20 minutes ofter 8 o'clock. We sqy the time is twenty minutes post eight. We reqd 8.35 os eight thirty-five. 6.5) tS Z) mrnures Delore v o ctoct-. We soy the time is twenty-five minutes to nine.
1.
Find out how mony times you con write your nome in 1 minute.
Whot time is it?
tGil*"-* \ 66
I o.m. meons ofter '12.00 midnight ond before '12.00 noon. p.m. meons ofter 12.00 noon ond before 12.00 midnight.
3.
Whot time is 25 minutes ofter 9.30 o.m.?
4.
How mony minutes ore there in t hour?
67
5. (o)
How mony minutes ore there from 1.15 p.m. to 1.42 p.m.?
(b)
How mony hours ore there from 3.18 p.m. to 8.18 p.m.?
(c)
How long is it trom 9.15 o.m. to 11.30 o.m.?
The hour (h) ond minute (min) ore units of time.
t
hour = 60 minutes
t;,k""*;;; \ 68
6. The toble shows the time token by 3 children Lo paint o
picture. Nome (o) Who took rne longest time? rhl Who took the shortest time?
7.
Mory took
t
h 35 min
to complete o jigsow puzzle.
\
'1
h=60min
--.r-_--o 8. Write in minutes.
(o) 2h (d) 3h
(b) 2 h 10 min (e) 3 n 5 min
(c)
(f)
2 n 45 min 3 n 15 min
9. Mrs Lin sewed 4 sets of curtcins. She took 50 minutes to sew eocn set of cu rtoins. Find the totol time token in hours ond minutes.
,--li;-.180 min
50minx4= 200 min =
10.
200 min
l8omin=Ih
I hlmin
Write in hours ond minutes. (b) 8s min (o) 70 min
(d)
125 min
(e)
20 mi )
160 min 69
(c)
(f)
100 min 210 min
11. A plone left Singopore ot 8.00 o.m. It orrived in Penong ot 9.05 o.m. How long did the journey toke?
The journey took 12.
h
I
min.
Mrs Fu went to morket ot 7.15 o.m. She come home t h 45 min loter.
Whot time is
When did she come home?
ofter /. tl
She come home t5.
I
ot
I
th45min o.m-a
o.rn.
Solly took t h 10 min to do her homework. She finished doing her homework ot 9.40 p.m. When did she stort? Whot time
thl0min
before 9.40 p.m.?
She storted
ot
I
p.m. 70
14. 10.45
o.m.
I 3.30 p.m. is I
(o) 2.00 p.m. is
h ofter 12.00 noon.
(b)
h
10.45 o.m. is
15.
2.00 p.m.
12.00 noon
I
I
h
3.3O p.m.
min ofter 12.00 noon.
I
min before 12.00 noon.
A supermorket is open from 10.15 o.m. to 9.30 p.m. every ooy.
How long is the supermorket open o doy?
'10.15
o.m.
9.30 p.m.
12.00 noon
th30min
th45min
t h 45 min +9 h 30 min =l
The supermorket is open
I
h 71
I
h
I
min
min o doy.
to. '12.O0
9.10 p.m.
midnight
4.00 o.m.
6.40 o.m.
islh ofter 12.00 midnight. 6.40 o.m. islh I min ofter 12.00 midnight.
(o) 4.00 o.m. (b)
(c) 9.10 p.m. is 17.
I
h
I
min before 12.00 midniqht.
A night tour begon ot 10.30 p.m. ond losted 3 h 20 mtn. When did the night tour end? 3h 20 min '12.O0
1O.30 p.m. 't h
3 h 20 min
midnight
30 min
- t h 30 min = I
The night tour ended ot 18.
1o.n,..
I
h
I
min
o"
o.m.
Add or subtrqct. (o) 2h 40 min + 3h (c) 3h 15 min 2h (") th 25 min + 2h15 min (s) 3h 50 min th35 min
-
-
(b) (d)
(f) (h)
2h20min+45min
3h5min-30min 2 h 40 min +2h25 min 3h20min-1h40min
t 72
-*t""***"
* \
PRACTICE 7A
1. Add or su btroct. (o) (c) (")
th 45min+2h 2h
(b) 3h 40 min - 2h (d) 3h -1h45 min
15 min + 45 min
th 30min+1h50min (f) 2h 10 min - th30
2.
This clock is 5 minutes slow. Whot is the correct time?
3.
How long is it?
4.
(o) (b) (c) (d)
From From From From
mtn
4.4O o.m. to 11.55 o.m. 5.45 p.m. to 7.00 p.m. 10.05 p.m. to 12.00 midnight 2.4O p.m- to 3.25 p.m.
Mr Chen took 2 h 35 min to repoir c vcn ond
t h 55 min to
repoir o cor. (o) How long did he toke to repcir both vehicles? (b) How much longer did he toke to repoir the van thqn
the cor?
5.
Chondron took 2 h 30 min to point his room. He begon ot 9.20 o.m. Whot time did he finish pointing his room?
5.
A group of children left for on excursion ot 8.30 c.m. They returned 4 h 10 min loter. Whot time did they return?
7. A supermcrket opens for business ot 9.30 o.m. Its workers hove to report for work 40 minutes eorlier. Whot time must the workers report for work? 73
O
Other Units of Time
3.20 qnd 10 seconds
3.20
f'-RL,'?\ 3.20 ond 50
second'
\-}|,',
1 minute = 60 seconds 1.
(ol
flno ouL now mony mes you con skip in'10 seconds. -_
(b) (c)
How long oo you toke to write the word SINCAPORE? How long oo you take to run 100 m?
.j-
74
_",
The hour (h), minute (min) ond second (s) qre units of time.
th=60min '1
min=60s
2. (o) Write 3 min 40 s in seconds.
3min40s=ls (b) Write
150 s in minutes ond seconds.
15Os=lminls
'.:" - . -
'":',,
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3.
(o) l yeor-I months (b) 2yeors-lmonths
(c) 2 yeors 4 months-l months (d) 40 months - | yeors I months
4. (o) lweek=Idoys (b) 3weeks-ldoys (c) 3weeks 4 doys= | (d) 30 doys -
|
weeks
doys
I
doys
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..
PRACTICE 78
1.
Find the missing numbers.
(o)
2h12min-lmin 2min3s=Ir
(b) 108min=lhlmin (d) 94s*lminls lyeorgmonths=lmonths
(f) 30 months
-|
yecrs
I
months
(s)
2weeks5doys=ldoys
(h)
40cioys-lweekslcioys
2.
The flying time from Singopore to Bongkok is t h 35 min ond from Singopore to Monilo is 3 h 15 min. How much longer does it toke to fly to Monilo thon to Bcngkok?
3.
A bookshop is open from 9.30 o.m. to 5.00 How long is the bookshop open?
4.
Mrs Mo went shopping ot 10.20 o.m. She returned home 4 hours loter. When did she return home?
5.
Devi completed o jigsow puzzle in t h 6 min. Lily completed the some jigsow puzzle 10 minutes foster. How long did Lily toke to complete the jigscw puzzle?
6.
Mr Li ond his fomily went to Chongi Beoch for o picnic. They left home ot 8.30 o.m. ond orrived ot Chongi Beoch ot 9.15 o.m. How long did the journey toke?
7.
Mr Chen took 8 h 45 min to drive from Singopore to Kuolo Lumpur. He orrived there ot 2.15 p.m. Whot time did he leove Singcpore?
REVIEW E 1. Whot time is it?
(o) (b)
2.
8 h 55 min ofter 12.00 noon 1 h 30 min cfter 12.00 midnight
Write the missing numerotor or denominotor. (c)
(b)
(o)
10
3.
This groph shows the number of vehicles in o cor pork. 50 40
Numberof 3o vehicles
20 10
0
Motorcycle
Bus
Cor
Von
(o) How mony more vons thon buses were there? (b) lf there were 90 porking lots for ccrs ond vons, how mony of them were not occupied?
4.
Mr Chen stoyed in Jopon for 19 months. Mr Lin stoyed there for 2 yeors 4 months. Who stoyed longer? How mony months longer? 77
5.
A mcchine con fill 140 jors of jom in 10 minutes. How mony jors con it fill in 1 minute? ort lesson storted ot 5.40 p.m. It losted 45 minutes.
6. An
When did the lesson end?
7.
A tonk con hold 10 times os much woter os o The copocitv of the tank is 60 litres. Whot is the ccpocity of the poil?
8.
A piece of ribbon
une
prece
(
rs
1 m long is cut into
pieces.
m rong.
Whot is the length of the other 9.
two
Doil.
piece?
Mr Fu bought o toothbrush ond o tube of toothpcste. A toothbrush cost $6.50. A tube of toothposte cost $1.80. How much did he poy oltogether?
10.
Mr Wu hod o box of mongoes. After giving 3 mongoes eoch to 16 children, he hod 20 mongoes left. How mony mongoes were there in the box ot first?
11.
Fotimoh spent $4.80 on strings ond $2.50 on beods to moke o flowerpot honger. How much did it cost her to moke c flowerpot hcnger?
12.
Mrs Chen bought 8 towels. She gove the coshier $50 ond received $2 chong e. (o) How much did she poy for the towels? (b) Whot wos the cost of 1 towel? 7A
Geometry
@ nngles Use
two cords to form on cngle like this:
Then moke o bigger ongle. Whot is the biggest ongle you con get? Compore it with your friends'.
Which cngle Which ongle
IS
t5
the smollest? the biggest?
1.
Here ore some exomples of ongles.
Look for some more ongles oround you. 2. Two sides
of a triongle moke on ongle.
A triongle hos
3.
I
sides ond
!
ongles.
Here ore some 4-sided figures. How mony ongles does ecch figure hove?
c
l=;ilr;;;-.. 80
O
Right Angtes Fold o piece of poper twice
to moke on ongle like this:
The ongle you hove mode is o speciol one. It is o right ongle. Use the right ongle you hove mode to find out which of the following ongles ore right ongles.
Use the right ongle you hove mode to Iook for right ongles oround you81
1.
How mony right ongles con you find in (o) o squore (b) o rectongle?
2. Which one of these triongles hos
Which one hos on ongle which right ongle?
is
o right ongle? greoter thqn o
3. How mony ongles does eoch of these figures hove? How mony ore right ongles?
a2
O
Areo Moke 4 squore cords ond 4 holf-squore cords.
ffiffiffiffi Use the cords
AAAA
to moke different fiqures like these:
Eoch
I
Eech
A
is'1 squqre unit.
is
The fig u res hove tne some (lre(t. squore units. The oreo of eoch figure is
I
83
I
sguore unit.
1. Whot
is the oreo
of eoch of the following figures?
WWM
w"*-^ B
Which figure hos the smollest oreo? Which figure hos the greotest o reo? a4
2.
This is o 1-cm
sq uo re. Eoch side of the is 1 cm long.
1cm
,.".lm Its orec is 1 squore centimetre (cm2). Cive the oreo of eqch of the following squores ln squore centimetres.
lcm
o 2-cm squore
o 3-cm
sq uo re
o 4-cm
sq uo re
The squore centimetre q unit of oreq.
A 2-cm squore is mode up of 4 pieces of 1-cm squores. Its oreo is 4 cm2.
3.
(o) Whot is the oreo of o 5-cm sq uo re? (b) Whot is the oreo of '1O-cm squo re? 85
4.
This figure is mode up of 1-cm squores. Find its oreo. 1cm
5.
Whot is the oreo of eoch of the following figures? lcm
,.",.1
W
M
M
M
W
M
w{
W
/,
Mk*
W
A
M
M
Fnt
W L
l-;,kb-k ""'.ts*" \ 85
6.
Eoch side of this squore is 1 m long. 1m TV:,+nnm
1^l1:ii!,/::i,,ii.
Il.l!iItt'!n
Its oreo is 1 squore metre (m2).
w Cive the oreo of eoch of the following figures in squore metres. 1m
1m
A
'1
B
Which figure hos the greotest oreo? Which figure hos the smollest oreo? 87
m
c
t;;"k*;;
\
Perimeter Sumei used 3 pieces of wire of the some length the triongle, the squore ond the rectongle. 1cm
They hove the some perimeter. The perimeter of eoch figure is
I
cm.
to moke
1.
Meosure with threod, the perimeter of eqch of these figures.
Y Which figure hos o longer perimeter? 2.
(o) Meosure the perimeter of your textbook in centimetres. (b) Meosure the perimeter of your clossroom in metres.
3. These two figures ore mode up of the sqme number sq uo res.
A
(o) (b)
B
They hove the some oreo. The oreo of eoch figure is I
cm'Z.
They hove different perimeters. The perimeter of Figure A is I cm. The perimeter of Figure B is I cm. 89
of 1-cm
4.
These figures cre mode up of 1-cm squcres.
c
(o) (b)
5.
D
Do they hove the some oreo? Do they hove the some perimeter?
These figures ore mode up of l-cm squores.
W P
(o) Which two figures hqve the some oreo but different (b) Which two figures hove the some perimeter but
different oreos? (c) Which two figures hove the some oreo ond perimeter? 90
6. (o)
Eoch side of the squore is 6 cm long. Find its perimeter.
Perimeter=6+6+6+6
(b)
1..
6cm
The length of the rectongle is 12 cm. Its breodth is 4 cm. Find its perimeter. Perimeter
7.
6cm
=12+4+12+4 - 1.'n
4' 12 cm
Find the perimeter of each of the following figures:
9m '10
cm
tlm
8cm '16
m
T--"*bfi;*; 91
-\
@ Rreo of o Rectongte Find the oreo of eoch of the followinq rectonqles:
I multiply the length ond breodth of eoch rectongle to find its qreo.
I count the squqre units
covered by eoch rectongle to
Areq of rectongle = Length 92
x
Breodth
1.
Find the oreo of the rectongle. Araa a{ tar+anala
=5x4 = | squore units
2.
Find the oreo of eoch of the following rectongles:
(o)
(b)
1cm
1.,"1
1cm
(.)
(d)
6cm
(e) 8cm
93
1cm
PRACTICE 9A
1.
Find the oreo ond the perimeter of eoch of the following rectongles ond squqres: 17 cm
10 cm
5cm
6cm
8m
2.
The length of the photogrop is 15 cm. Its breodth is 10 cm. Find its oreo.
3. The Iength is 10 m.
I
10 cm
of o rectongulor field is 85 m ond its breodth
Ali rcn oround the field once. How for did he run? 94
REVIEW 1.
F
Arronge the froctions in order, beginning with the smallest.
,,3 \o)
'r
4' t'
s 8
/h\II
3 10
2. Eoch side of o triongle is 9 cm long. Find the perimeter of the triongle.
3.
This groph shows the heights of the pupils in Mrs Lin's 10
8 Number of pupils
148cm 149cm 150cm 151cm 152cm 148cm
Study the groph ond onswer these questions. (o) How mony pupils ore 150 cm toll? (b) How mony pupils ore toller thon 150 cm? (c) How mony pupils ore in the tollest group?
4.
Tom bought o wire ond cut it into 8 pieces. Eoch piece of wire wos 30 cm long. Find the length of the wire he bought. Cive the onswer in metres ond centimetres.
5.
2500 people took port in o civil defence exercise. 1360 of them were men. 240 were children. The rest were women. (o) How mony women were there? (b) How mony more odults thon children were there? 95
clo ss.
6.
l.
Mrs Chen mode 286 cookies. She gove owoy 30 cookies ond sold the rest ot 8 for How much money did she receive?
$1.
Eoch side of o squore is 6 cm long. Find the crec of the squore.
o Pizzo. Anno ond Peter eoch received of the pizzo.
8. Anno, Peter ond John shored
]
Whot froction of the pizzo did John receive? 9. 580 m Po
rk
Librory
Tom's house
Tom's house is 1 km from the Pork. .How for is Tom's house from the librory?
10. (o) Whot
(b)
is the totol weight of the 3 pieces of butter ond the pocket of flour? lf ecch piece of butter weighs 300 g, find the weight of the pocket of flour in kilogroms cnd groms.
11.
A
B
c
(o) Which two fig u res hove the some oreo? (b) Which two fig u res hove the some perimeter? 96
